Mobile terminal

ABSTRACT

A mobile terminal comprises a body including a first frame and a second frame slidably coupled to a rear surface of the first frame in a first direction or a second direction; a flexible display unit including a front portion located on a front surface of the body, a rear portion located on a rear surface of the body, and a side portion connecting the front portion with the rear portion and surrounding one side of the body; a plurality of reinforcing ribs protruded from a rear surface of the first frame and extended in the first direction; and a plurality of supports protruded from a front surface of the second frame and located between the respective reinforcing ribs. The mobile terminal may enhance usability and portability by varying its size.

CROSS-REFERENCE TO RELATED APPLICATION(S)

Pursuant to 35 U.S.C. § 119 (a), this application claims the benefit ofan earlier filing date and right of priority to InternationalApplication No. PCT/KR2020/016947 filed on Nov. 26, 2020, the contentsof which are hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a mobile terminal, and moreparticularly, to a mobile terminal that has a flexible display and iscapable of extending a size of a screen while the display is scrolledand slid at the same time.

Discussion of the Related Art

Terminals may be generally classified as mobile/portable terminals orstationary terminals according to their mobility. Mobile terminals mayalso be classified as handheld terminals or vehicle mounted terminalsaccording to whether or not a user can directly carry the terminal.

In recent years, because of a development of a broadcasting technologyand a network technology, functions of the display device have also beenconsiderably diversified, and a performance of the device has beenimproved accordingly. That is, the display device has been developed toprovide not only broadcast contents but also various other contents tothe user. For example, the display device may provide game play, musiclistening, internet shopping, user customized information, and the likeusing various applications as well as programs received from thebroadcasting station. In order to perform such extended functions, thedisplay device may be basically connected to other devices or networksusing various communication protocols, and may provide the user with aubiquitous computing environment. In other words, the display device hasevolved into a smart device that enables connectivity to a network andcontinuous computing.

Recently, a flexible display having sufficient elasticity and capable oflarge deformation has been developed. The size of a mobile terminal canbe varied using the deformable nature of the flexible display. For themobile terminal having such a variable structure, changing the size ofthe mobile terminal should be stably performed, and there is a need fora structure to support the extended display unit to maintain a flatstate of the display unit.

Also, components exposed to the outside need to be minimized to preventany contaminant from entering the inside due to the variable structure.

SUMMARY OF THE INVENTION

Accordingly, the present disclosure is directed to a mobile terminalthat substantially obviates one or more problems due to limitations anddisadvantages of the related art.

An object of the present disclosure is to provide a mobile terminal forimproving the durability of a flexible display by preventing a point atwhich the flexible display is bent from being limited to a specificposition.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amobile terminal comprises a body including a first frame and a secondframe slidably coupled to a rear surface of the first frame in a firstdirection or a second direction; a flexible display unit including afront portion located on a front surface of the body, a rear portionlocated on a rear surface of the body, and a side portion connecting thefront portion with the rear portion and surrounding one side of thebody; a plurality of reinforcing ribs protruded from a rear surface ofthe first frame and extended in the first direction; and a plurality ofsupports protruded from a front surface of the second frame and locatedbetween the respective reinforcing ribs.

Each support may have a protruding height corresponding to that of eachreinforcing rib.

Each reinforcing rib may include a rib protrusion protruded in a thirddirection vertical to the first direction, each support may include arib groove inserted to correspond to a shape of the rib protrusion, andthe rib protrusion and the rib groove guide movement of the first framein the first direction and the second direction with respect to thesecond frame and limits movement of the first frame in the thirddirection.

The rib protrusion and the rib groove may further include a low frictionlayer on their surfaces.

The flexible display unit may include a first area coupled to the frontsurface of the first frame; and a second area of which position isvariable to the front surface or the rear surface of the body when asize of the body is changed, and a rolling hinge is located on a rearsurface of the second area and enables bending deformation to correspondto a shape of the second area, and its thickness and a thickness of thesupport may correspond to those of the first frame and the reinforcingrib.

The rolling hinge may include a plurality of support bars extended inthe third direction vertical to the first direction and disposed inparallel with one another in the first direction, and an intervalbetween the support bars may be widened as the support bars are far awayfrom a rear direction of the flexible display unit.

The mobile terminal may further comprise a driving unit moving the firstframe in the first direction or the second direction with respect to thesecond frame to adjust the size of the body, wherein the driving unitmay include a motor packaged in the second frame; a pinion gear rotatedby a driving force of the motor; and a rack gear located on the rearsurface of the first frame and extended in the first direction, makinglinear movement by the driving force of the motor, which is deliveredthrough the pinion gear.

The mobile terminal may further comprise a motor housing configured toseat the motor and the pinion gear thereon and fastened to the secondframe; and a guide rail fastened to the rack gear, guiding linearmovement of the rack gear.

The mobile terminal may further comprise a rail bearing located betweenthe guide rail and the rack gear.

The driving unit may include a plurality of motors disposed in parallelwith one another in the first direction; and a plurality of pinion gearsfastened to the plurality of motors, providing the driving force to therack gear.

The driving unit may include a plurality of driving units disposed to bespaced apart from one another in the third direction vertical to thefirst direction.

The mobile terminal may further comprise a slide frame slidably coupledon the rear surface of the second frame in the first direction or thesecond direction, wherein an end portion of the flexible display unit isfixed to a rear surface of the slide frame.

The mobile terminal may further comprise a first edge deco fixing theend portion of the flexible display unit in the second direction to thefirst frame.

The mobile terminal may further comprise a side frame protecting theside portion of the flexible display unit.

The mobile terminal may further comprise a rear cover covering a rearsurface of the second frame and including a light-transmissive material.

As described above, the mobile terminal of the present disclosure mayenhance usability and portability by varying its size.

Also, since a curved portion of the flexible display is not limited to aspecific portion, stress only applied to the specific portion may bedistributed when a size of the mobile terminal is changed.

Also, since a display unit may stably be maintained at a flat state evenin the case that mobile terminal is extended, a continuous large screenmay be implemented at the extended state.

Also, since the mobile terminal may naturally be slid withoutdistortion, the mobile terminal may be prevented from being damaged ordisordered in the middle of being used.

Also, the rack gear may be prevented from being exposed to the outsidein a state that the rack gear is extended, whereby a contaminant may beprevented from entering the mobile terminal and durability may beimproved.

Further scope of applicability of the present disclosure will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the disclosure, aregiven by illustration only, since various changes and modificationswithin the spirit and scope of the disclosure will become apparent tothose skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description given herein below and the accompanying drawings,which are given by illustration only, and thus are not limitative of thepresent disclosure, and wherein:

FIG. 1 is a block diagram of a mobile terminal in accordance with thepresent disclosure;

FIG. 2 is a front view of a first state and a second state of the mobileterminal in accordance with an embodiment;

FIG. 3 is a rear view of the first state and the second state of themobile terminal in accordance with an embodiment;

FIG. 4 is a side view of the mobile terminal as viewed from a thirddirection;

FIGS. 5 and 6 are exploded perspective views of the mobile terminal inaccordance with an embodiment;

FIG. 7 is a view showing the inside of the mobile terminal according toan embodiment;

FIG. 8 is a view showing the inside of the mobile terminal according toanother embodiment;

FIG. 9 is a view showing a driving unit of the mobile terminal inaccordance with an embodiment;

FIG. 10 is a cross-sectional view taken along lines A-A and B-B in FIG.2;

FIG. 11 is a view showing a display unit and a rolling hinge of themobile terminal in accordance with an embodiment;

FIGS. 12 and 13 are views showing a first frame and a second frame at asecond state of the mobile terminal; and

FIG. 14 is a view showing a section of a third direction of areinforcing rib and a support in FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

Description will now be given in detail according to exemplaryembodiments disclosed herein, with reference to the accompanyingdrawings. For the sake of brief description with reference to thedrawings, the same or equivalent components may be provided with thesame reference numbers, and description thereof will not be repeated. Ingeneral, a suffix such as “module” and “unit” may be used to refer toelements or components. Use of such a suffix herein is merely intendedto facilitate description of the specification, and the suffix itself isnot intended to give any special meaning or function. In the presentdisclosure, that which is well-known to one of ordinary skill in therelevant art has generally been omitted for the sake of brevity. Theaccompanying drawings are used to help easily understand varioustechnical features and it should be understood that the embodimentspresented herein are not limited by the accompanying drawings. As such,the present disclosure should be construed to extend to any alterations,equivalents and substitutes in addition to those which are particularlyset out in the accompanying drawings.

It will be understood that although the terms first, second, etc. may beused herein to describe various elements, these elements should not belimited by these terms. These terms are generally only used todistinguish one element from another.

It will be understood that when an element is referred to as being“connected with” another element, the element can be directly connectedwith the other element or intervening elements may also be present. Incontrast, when an element is referred to as being “directly connectedwith” another element, there are no intervening elements present.

A singular representation may include a plural representation unless itrepresents a definitely different meaning from the context.

Terms such as “include” or “has” are used herein and should beunderstood that they are intended to indicate an existence of severalcomponents, functions or steps, disclosed in the specification, and itis also understood that greater or fewer components, functions, or stepsmay likewise be utilized.

FIG. 1 is a block diagram of a mobile terminal in accordance with thepresent disclosure.

The mobile terminal 100 is shown having components such as a wirelesscommunication unit 110, an input unit 120, a sensing unit 140, an outputunit 150, an interface unit 160, a memory 170, a controller 180, and apower supply unit 190. Referring now to FIG. 1, the mobile terminal 100is shown having wireless communication unit 110 configured with severalcommonly implemented components. It is understood that implementing allof the illustrated components is not a requirement, and that greater orfewer components may alternatively be implemented.

More specifically, the wireless communication unit 110 typicallyincludes one or more modules which permit communications such aswireless communications between the mobile terminal 100 and a wirelesscommunication system, communications between the mobile terminal 100 andanother mobile terminal, communications between the mobile terminal 100and an external server. Further, the wireless communication unit 110typically includes one or more modules which connect the mobile terminal100 to one or more networks.

To facilitate such communications, the wireless communication unit 110includes one or more of a broadcast receiving module 111, a mobilecommunication module 112, a wireless Internet module 113, a short-rangecommunication module 114, and a location information module 115.

Regarding the wireless communication unit 110, the broadcast receivingmodule 111 is typically configured to receive a broadcast signal and/orbroadcast associated information from an external broadcast managingentity via a broadcast channel. The broadcast channel may include asatellite channel, a terrestrial channel, or both. In some embodiments,two or more broadcast receiving modules 111 may be utilized tofacilitate simultaneously receiving of two or more broadcast channels,or to support switching among broadcast channels.

The mobile communication module 112 can transmit and/or receive wirelesssignals to and from one or more network entities. Typical examples of anetwork entity include a base station, an external mobile terminal, aserver, and the like. Such network entities form part of a mobilecommunication network, which is constructed according to technicalstandards or communication methods for mobile communications (forexample, Global System for Mobile Communication (GSM), Code DivisionMulti Access (CDMA), CDMA2000 (Code Division Multi Access 2000), EV-DO(Enhanced Voice-Data Optimized or Enhanced Voice-Data Only), WidebandCDMA (WCDMA), High Speed Downlink Packet access (HSDPA), HSUPA (HighSpeed Uplink Packet Access), Long Term Evolution (LTE), LTE-A (Long TermEvolution-Advanced), and the like).

Examples of wireless signals transmitted and/or received via the mobilecommunication module 112 include audio call signals, video (telephony)call signals, or various formats of data to support communication oftext and multimedia messages.

The wireless Internet module 113 is configured to facilitate wirelessInternet access. This module may be internally or externally coupled tothe mobile terminal 100. The wireless Internet module 113 may transmitand/or receive wireless signals via communication networks according towireless Internet technologies.

Examples of such wireless Internet access include Wireless LAN (WLAN),Wireless Fidelity (Wi-Fi), Wi-Fi Direct, Digital Living Network Alliance(DLNA), Wireless Broadband (WiBro), Worldwide Interoperability forMicrowave Access (WiMAX), High Speed Downlink Packet Access (HSDPA),HSUPA (High Speed Uplink Packet Access), Long Term Evolution (LTE),LTE-A (Long Term Evolution-Advanced), and the like. The wirelessInternet module 113 may transmit/receive data according to one or moreof such wireless Internet technologies, and other Internet technologiesas well.

In some embodiments, when the wireless Internet access is implementedaccording to, for example, WiBro, HSDPA, HSUPA, GSM, CDMA, WCDMA, LTE,LTE-A and the like, as part of a mobile communication network, thewireless Internet module 113 performs such wireless Internet access. Assuch, the Internet module 113 may cooperate with, or function as, themobile communication module 112.

The short-range communication module 114 is configured to facilitateshort-range communications. Suitable technologies for implementing suchshort-range communications include BLUETOOTH™, Radio FrequencyIDentification (RFID), Infrared Data Association (IrDA), Ultra-WideBand(UWB), ZigBee, Near Field Communication (NFC), Wireless-Fidelity(Wi-Fi), Wi-Fi Direct, Wireless USB (Wireless Universal Serial Bus), andthe like. The short-range communication module 114 in general supportswireless communications between the mobile terminal 100 and a wirelesscommunication system, communications between the mobile terminal 100 andanother mobile terminal 100, or communications between the mobileterminal and a network where another mobile terminal 100 (or an externalserver) is located, via wireless area networks. One example of thewireless area networks is a wireless personal area networks.

The location information module 115 is generally configured to detect,calculate, derive or otherwise identify a position of the mobileterminal. As an example, the location information module 115 includes aGlobal Position System (GPS) module, a Wi-Fi module, or both. Ifdesired, the location information module 115 may alternatively oradditionally function with any of the other modules of the wirelesscommunication unit 110 to obtain data related to the position of themobile terminal. As one example, when the mobile terminal uses a GPSmodule, a position of the mobile terminal may be acquired using a signalsent from a GPS satellite. As another example, when the mobile terminaluses the Wi-Fi module, a position of the mobile terminal can be acquiredbased on information related to a wireless access point (AP) whichtransmits or receives a wireless signal to or from the Wi-Fi module.

The input unit 120 includes a camera 121 for obtaining images or video,a microphone 122, which is one type of audio input device for inputtingan audio signal, and a user input unit 123 (for example, a touch key, apush key, a mechanical key, a soft key, and the like) for allowing auser to input information. Data (for example, audio, video, image, andthe like) is obtained by the input unit 120 and may be analyzed andprocessed by controller 180 according to device parameters, usercommands, and combinations thereof.

Such cameras 121 may process image frames of still pictures or videoobtained by image sensors in a video or image capture mode. Theprocessed image frames can be displayed on the display unit 151 orstored in memory 170. In some cases, the cameras 121 may be arranged ina matrix configuration to permit a plurality of images having variousangles or focal points to be input to the mobile terminal 100. Asanother example, the cameras 121 may be located in a stereoscopicarrangement to acquire left and right images for implementing astereoscopic image.

The microphone 122 is generally implemented to permit audio input to themobile terminal 100. The audio input can be processed in various mannersaccording to a function being executed in the mobile terminal 100. Ifdesired, the microphone 122 may include assorted noise removingalgorithms to remove unwanted noise generated in the course of receivingthe external audio.

The user input unit 123 is a component that permits input by a user.Such user input may enable the controller 180 to control operation ofthe mobile terminal 100. The user input unit 123 may include one or moreof a mechanical input element (for example, a key, a button located on afront and/or rear surface or a side surface of the mobile terminal 100,a dome switch, a jog wheel, a jog switch, and the like), or atouch-sensitive input, among others. As one example, the touch-sensitiveinput may be a virtual key or a soft key, which is displayed on a touchscreen through software processing, or a touch key which is located onthe mobile terminal at a location that is other than the touch screen.On the other hand, the virtual key or the visual key may be displayed onthe touch screen in various shapes, for example, graphic, text, icon,video, or a combination thereof.

The sensing unit 140 is typically implemented using one or more sensorsconfigured to sense internal information of the mobile terminal, thesurrounding environment of the mobile terminal, user information, andthe like. For example, the sensing unit 140 may alternatively oradditionally include other types of sensors or devices, such as aproximity sensor 141 and an illumination sensor 142, a touch sensor, anacceleration sensor, a magnetic sensor, a G-sensor, a gyroscope sensor,a motion sensor, an RGB sensor, an infrared (IR) sensor, a finger scansensor, a ultrasonic sensor, an optical sensor (for example, camera121), a microphone 122, a battery gauge, an environment sensor (forexample, a barometer, a hygrometer, a thermometer, a radiation detectionsensor, a thermal sensor, and a gas sensor, among others), and achemical sensor (for example, an electronic nose, a health care sensor,a biometric sensor, and the like), to name a few. The mobile terminal100 may be configured to utilize information obtained from sensing unit140, and in particular, information obtained from one or more sensors ofthe sensing unit 140, and combinations thereof.

The output unit 150 is typically configured to output various types ofinformation, such as audio, video, tactile output, and the like. Theoutput unit 150 is shown having a display unit 151, an audio outputmodule 152, a haptic module 153, and an optical output module 154. Thedisplay unit 151 may have an inter-layered structure or an integratedstructure with a touch sensor in order to facilitate a touch screen. Thetouch screen may provide an output interface between the mobile terminal100 and a user, as well as function as the user input unit 123 whichprovides an input interface between the mobile terminal 100 and theuser.

The audio output module 152 is generally configured to output audiodata. Such audio data may be obtained from any of a number of differentsources, such that the audio data may be received from the wirelesscommunication unit 110 or may have been stored in the memory 170. Theaudio data may be output during modes such as a signal reception mode, acall mode, a record mode, a voice recognition mode, a broadcastreception mode, and the like. The audio output module 152 can provideaudible output related to a particular function (e.g., a call signalreception sound, a message reception sound, etc.) performed by themobile terminal 100. The audio output module 152 may also be implementedas a receiver, a speaker, a buzzer, or the like.

A haptic module 153 can be configured to generate various tactileeffects that a user feels, perceive, or otherwise experience. A typicalexample of a tactile effect generated by the haptic module 153 isvibration. The strength, pattern and the like of the vibration generatedby the haptic module 153 can be controlled by user selection or settingby the controller. For example, the haptic module 153 may outputdifferent vibrations in a combining manner or a sequential manner.

An optical output module 154 can output a signal for indicating an eventgeneration using light of a light source. Examples of events generatedin the mobile terminal 100 may include message reception, call signalreception, a missed call, an alarm, a schedule notice, an emailreception, information reception through an application, and the like.

The interface unit 160 serves as an interface with various types ofexternal devices that can be coupled to the mobile terminal 100. Theinterface unit 160, for example, may include any of wired or wirelessports, external power supply ports, wired or wireless data ports, memorycard ports, ports for connecting a device having an identificationmodule, audio input/output (I/O) ports, video I/O ports, earphone ports,and the like. In some cases, the mobile terminal 100 may performassorted control functions associated with a connected external device,in response to the external device being connected to the interface unit160.

The memory 170 is typically implemented to store data to support variousfunctions or features of the mobile terminal 100. For instance, thememory 170 may be configured to store application programs executed inthe mobile terminal 100, data or instructions for operations of themobile terminal 100, and the like. Some of these application programsmay be downloaded from an external server via wireless communication.Other application programs may be installed within the mobile terminal100 at time of manufacturing or shipping, which is typically the casefor basic functions of the mobile terminal 100 (for example, receiving acall, placing a call, receiving a message, sending a message, and thelike). It is common for application programs to be stored in the memory170, installed in the mobile terminal 100, and executed by thecontroller 180 to perform an operation (or function) for the mobileterminal 100.

The controller 180 typically functions to control overall operation ofthe mobile terminal 100, in addition to the operations associated withthe application programs. The controller 180 may provide or processinformation or functions appropriate for a user by processing signals,data, information and the like, which are input or output, or activatingapplication programs stored in the memory 170.

To drive the application programs stored in the memory 170, thecontroller 180 may be implemented to control a predetermined number ofthe components mentioned above in reference with FIG. 1. Moreover, thecontroller 180 may be implemented to combinedly operate two or more ofthe components provided in the mobile terminal 100 to drive theapplication programs.

The power supply unit 190 can be configured to receive external power orprovide internal power in order to supply appropriate power required foroperating elements and components included in the mobile terminal 100.The power supply unit 190 may include a battery, and the battery may beconfigured to be embedded in the terminal body, or configured to bedetachable from the terminal body.

Some or more of the components may be operated cooperatively to embodyan operation, control or a control method of the mobile terminal inaccordance with embodiments of the present disclosure. Also, theoperation, control or control method of the mobile terminal may berealized on the mobile terminal by driving of one or more applicationproblems stored in the memory 170.

FIG. 2 is a front view of a first state and a second state of the mobileterminal in accordance with an embodiment, and FIG. 3 is a rear view ofthe first state and the second state of the mobile terminal inaccordance with an embodiment. FIGS. 2(a) and 3(a) are views showing thefirst state in which the mobile terminal is contracted, and FIGS. 2(b)and 3(b) are views showing the second state in which the mobile terminalis extended.

The mobile terminal 100 of the present disclosure includes a body ofwhich size is varied. The body includes a first frame 101 and a secondframe 102, and its size may be varied while the second frame 102 ismoving in a first direction or second direction of the first frame 101.The first state is the state that the body (mobile terminal) isdownsized, and the second state is the state that the body (mobileterminal) is extended.

Movement of the first frame 101 is relative to that of the second frame102, and the second frame 102 moves in the first direction based on thefirst frame 101 during switching from the first state to the secondstate, and the first frame 101 moves in the second direction based onthe second frame 102. Therefore, extension in the first direction meansextension in a horizontal direction on the drawing.

As shown in the figures, the mobile terminal 100 in the first state isin a contracted position, and has a smaller size than the mobileterminal 100 in the second state. In addition, the size of the displayunit 151 positioned on the front of the mobile terminal 100 is alsosmaller than in the second state. The mobile terminal 100 in the firststate may be extended in a first direction D1 to switch to the secondstate. In the second state, as shown in FIG. 2(b), the size of themobile terminal 100 and the size of the display unit 151 positioned onthe front of the mobile terminal 100 are larger than in the first state,while the size of the display unit 151 positioned on the rear of themobile terminal 100 is reduced as shown in FIG. 3(b). That is, a part ofthe display units 151 positioned on the rear of the mobile terminal 151in the first state moves to the front of the mobile terminal 100 in thesecond state.

In the following description, the direction in which the mobile terminal100 and the display unit 151 thereof are extended or enlarged is definedas a first direction D1, and the direction in which the mobile terminalcontracts or retracts or is reduced to switch from the second state tothe first state is defined as a second direction D2. A directionperpendicular to the first and second directions D1 and D2 is defined asa third direction. Description will be made on the assumption that thefirst and second directions are horizontal directions and the thirddirection is a vertical direction. However, depending on the arrangementof the mobile terminal 100, the first and second directions may bevertical directions and the third direction may be a horizontaldirection.

As such, a flexible display unit 151 which is bendable may be used asthe display unit such that the position of the display unit may bevaried. The flexible display unit 151 may be a display unit capable ofmaintaining a flat state like a conventional flat panel display andcapable of warping, bending, folding, twisting, or rolling like paper.The flexible display unit 151 refers to a display which is manufacturedon a thin and flexible substrate and is thus lightweight and robust asnot to be easily broken. The flexible display unit according the presentdisclosure may be bent in a specific direction, and may be arranged suchthat the curvature thereof may change in the first direction.

In addition, an electronic paper is a display technology to whichproperties of general ink are applied. The electronic paper may bedifferent from the conventional flat panel display in using reflectedlight. The electronic paper may change information using a twisted ballor electrophoresis using a capsule.

In a state in which the flexible display unit 151 is not deformed (e.g.,a state of having an infinite curvature radius, hereinafter referred toas a basic state), a display area of the flexible display unit 151becomes flat. In a state in which the flexible display unit 151 isdeformed by an external force from the basic state (e.g., a state ofhaving a finite radius of curvature, hereinafter referred to as adeformed state), the display area may become a curved face. As shown,information displayed in the deformation state may be visual informationoutput on the curved face. Such visual information is implemented byindependently controlling light emission of sub-pixels arranged in amatrix. The sub-pixel refers to a minimum unit for implementing onecolor. When external force is applied to the flexible display unit 151,the flexible display unit 151 may be deformed to switch from the defaultstate, which is the flat state, to a bent state, which is not the flatstate.

The flexible display unit 151 may be combined with a touch sensor toimplement a flexible touch screen. When a touch is made on the flexibletouch screen, the controller 180 (see FIG. 1) may perform controlcorresponding to such touch input. The flexible touch screen may beconfigured to detect the touch input in the deformed state as well as inthe basic state.

The touch sensor detects the touch (or touch input) applied on the touchscreen using at least one of various touch schemes such as a resistivefilm scheme, a capacitance scheme, an infrared scheme, an ultrasonicwave scheme, a magnetic field scheme, and the like.

As an example, the touch sensor may be configured to convert a change inpressure applied on a specific portion of the touch screen, capacitancegenerated at the specific portion, or the like into an electrical inputsignal. The touch sensor may be configured such that a touch objectapplying a touch on the touch screen may detect touched position andarea on the touch sensor, a pressure during the touch, a capacitanceduring the touch, and the like.

Further, the mobile terminal 100 may have a deformation detection meansfor detecting the deformation of the flexible display unit 151. Suchdeformation detection means may be included in the sensing unit 140 (seeFIG. 1).

The deformation detection means may be disposed in the flexible displayunit 151 or a case (first to second frames 101 to 102 to be describedlater) to detect information related to the deformation of the flexibledisplay unit 151. In this connection, the information related to thedeformation may include a direction in which the flexible display unit151 is deformed, a degree of the deformation, a deformed position, adeformed time, an acceleration at which the deformed flexible displayunit 151 is restored, and the like. In addition, the information relatedto the deformation may include various kinds of information that may bedetected due to the bending of the flexible display unit 151.

In addition, the controller 180 may change information displayed on theflexible display unit 151 or generate a control signal for controlling afunction of the mobile terminal 100 based on the information related tothe deformation of the flexible display unit 151 detected by thedeformation detection means.

The deformation of the flexible display unit 151 may vary depending onthe positions of the first frame 101 and the second frame 102. As shownin FIG. 2, since the bending position on the flexible display unit 151is determined according to the positions of the first frame and thesecond frame, the bending deformation position of the flexible displayunit 151 and the area thereof positioned on the front may be calculatedbased on the positions of the first frame 101 and the first frame 102 inplace of the deformation detection means of the flexible display unit151.

The state conversion (first or second state) of the flexible displayunit 151, i.e., the size change at the front and rear faces of themobile terminal 100 of the display unit 151 based on the size change ofthe mobile terminal 100 may be performed manually by a force applied bythe user, but may be not limited to such manual scheme. For example,when the mobile terminal 100 or the flexible display unit 151 is in thefirst state, the mobile terminal 100 or the flexible display unit 151may be converted into the second state by the user or an applicationcommand without the external force applied by the user. As such, inorder for the flexible display unit 151 to be automatically deformedwithout the external force, the mobile terminal 100 may include adriving unit 200, which will be described later.

The flexible display unit 151 of the present disclosure is bent 180degrees by rolling around a side portion of the mobile terminal 100facing in the first direction. Accordingly, based on the side portion ofthe mobile terminal 100, a part of the flexible display unit 151 isdisposed on the front of the mobile terminal 100, and the other part ofthe flexible display unit 151 is disposed on the rear of the mobileterminal 100. For simplicity, the part of the flexible display unit 151positioned on the front is called a front face, and the other part ofthe flexible display unit 151 positioned on the rear is called a rearface. As illustrated in FIG. 2, the mobile terminal may extend in thefirst direction or contract in the second direction opposite to thefirst direction. In this case, the area of the flexible display unit 151positioned on the front changes. That is, the sizes of the front faceand the rear face may be changed according to a change in the state ofthe mobile terminal.

The part of the flexible display unit 151 positioned on the front of themobile terminal 100 may be immovably fixed to the front surface of thefirst frame 101, and the other part thereof positioned on the rear ofthe mobile terminal 100 may be movably arranged on the rear of themobile terminal 100.

In addition, the flexible display unit 151 may be rolled on or releasedat the side portion in the first direction of mobile terminal.Accordingly, the rear face of the display unit 151 moves, so that thesize of the front face of the display unit 151 may be adjusted. Sincethe size of the flexible display unit 151 is determined and the flexibledisplay unit 151 is formed of one continuous body, an area of rear faceof the display unit 151 decreases as an area of the front face of thedisplay unit 151 increases. Such a display unit 151 may be rolled in asecond frame 102, which is movable relative to a first frame 101 to bedescribed later, more correctly, on one of sides of the second frame102. The display unit 151 may be withdrawn or pulled out from orinserted or pushed into the second frame 102 while being rolled in thesecond frame 102 along a moving direction of the second frame 102 toadjust the area of the display unit 151 on the front face of the mobileterminal 100. Such operation will be described in more detail belowalong with other relevant components of the mobile terminal 100.

Typically, an antenna is disposed in the case or the housing of themobile terminal 100, but a portion where the antenna is installed in thecase or the housing may be limited because of the flexible display unit151 that covers not only the front face of the mobile terminal 100 butalso the rear face thereof. For this reason, the antenna may beimplemented on the flexible display unit 151. An antenna on display(AOD) is an antenna in which a transparent film is formed by stacking anelectrode layer and a dielectric layer that have patterns engravedthereon, respectively. The antenna on display may be implemented thinnerthan an antenna implemented using a laser direct structuring (LDS)technology using a conventional copper nickel plating scheme, so thatthe antenna on display may not be exposed to the outside withoutaffecting a thickness. In addition, the antenna on display may transmitand receive a signal directly to or from the display unit 151.Accordingly, the antenna on display may be used in the mobile terminal100 in which the display unit 151 is located on the both faces of themobile terminal 100 as in the present disclosure.

The mobile terminal 100 may include a rear camera 121 b located on therear surface thereof as shown in FIG. 3. A rear portion of the displayunit 151 may be located in the first direction at the first state, andcomponents such as the camera 121 b, the user input unit 123 and theantenna fingerprint sensor may be packaged in a space of the seconddirection.

FIG. 4 is a side view of the mobile terminal 100 as viewed from a thirddirection. The first frame 101 of the present disclosure is a plateshaped member thinner than the second frame 102, supports the rearsurface of a first area of the display unit 151 and the first area isslid, whereby an area of a front portion of the flexible display unit151 is extended. The second frame 102 is thicker than the first frame101, and includes a front portion and a rear portion 1022, whereinvarious components may be accommodated between the front portion and therear portion, and the flexible display unit 151 may be rolled andextended in a rear direction from an end portion in the first directionof the second frame 102. The second frame 102 may further include a sideframe 1024 that includes a curved surface at the end portion of thefirst direction and protects a side portion of the flexible display unit151, which is bent to surround the second frame 102.

The first frame 101 is thin and its components are substantiallypackaged in the second frame 102, and the rear surface of the mobileterminal of the first state may be configured by the rear portion 1022of the second frame 102. The rear portion 1022 of the second frame 102may include a first rear portion 1022 a in which the rear portion of theflexible display unit 151 is located in the first direction, and asecond rear portion 1022 b always exposed to the rear direction at thefirst state and the second state.

The rear camera 121 b headed for the rear direction of the mobileterminal may be packaged in the second rear portion 1022 b, and mayinclude a plurality of cameras having different viewing angles such aswide angle, super-wide angle and telescope. In addition to the rearcamera 121 b, a proximity sensor 141, an audio output module 152, etc.may be located in the second rear portion 1022 b, and an antenna may beprovided therein.

In the first state, as shown in FIG. 3(a), the rear camera 121 bdisposed in parallel with the rear portion of the display unit 151 mayenable selfie photographing, and in order to take a target viewed by auser, the user may take the front portion of the display unit 151 evenat the second state as well as the first state while viewing the frontportion of the display unit 151. In the second state, as shown in FIG.3(b), the rear camera 121 b is disposed at the center portion of themobile terminal 100 such that the user easily focuses a position of asubject on the center while viewing the display unit duringphotographing.

The first rear portion 1022 a of the second frame is a space to whichthe rear portion of the display unit 151 moves. The first rear portion1022 a may further include a rear cover 1025 to prevent the first rearportion 1022 a of the second frame 102 from being exposed to the outsidewithout disturbing movement of the display unit 151. The display unit151 and a slide frame 103 may move between the rear cover 1025 and thefirst rear portion 1022 a. The rear cover 1025 may cover the first rearportion 1022 a only, or may protect components such as a camera bycovering the second rear portion 1022 b as well as the first rearportion 1022 a.

The rear cover 1025 may be made of an opaque material but if it is madeof a light-transmissive material, information may be provided to a userby using the display unit located on the rear surface of the mobileterminal. The rear cover 1025 may be configured such that its inside isseen to the user only if the display unit 151 is activated throughmirror-coating but is not seen to the user when the display unit 151 isnot activated. Mirror-coating of the rear cover 1025 may be omitted forthe portion where the rear camera 121 b is located, whereby transparencymay be enhanced.

As shown in FIG. 2(b) and FIG. 3(b), the mobile terminal 100 may furtherinclude a pop-up camera 121 a protruded from the end of the thirddirection. Since a camera needs a lens of a predetermined size or moreto make sure of quality such as resolution, if the camera is located inan upper bezel of the display unit 151, it is difficult to reduce a sizeof the upper bezel of the mobile terminal. In order to minimize the sizeof the upper bezel on the front surface of the mobile terminal, thecamera may be implemented in the form of pop-up for selectivelyaccommodating or drawing out the camera.

If the pop-up camera 121 a is not used, the pop-up camera 121 a may beprotruded upwardly when the user activates a camera function in a statethat it is located inside the second frame 102. Although the pop-upcamera 121 a is protruded at the second state as shown, it may be drawnout from the second frame 102 even at the second state when the camerafunction is activated.

The pop-up camera 121 a may be drawn out from the second frame 102 by anelastic member, or may be drawn out using a separate motor. If the motor201 is used, the pop-up camera 121 a may automatically be drawn out oraccommodated in the frame depending on whether the camera function isactivated. The pop-up camera 121 a may be disposed toward the front ofthe mobile terminal but may be rotated to be disposed toward the rear.

Alternatively, if the pop-up camera 121 a is accommodated in the secondframe 102, an image may be taken through a lens hole formed in thesecond rear portion toward the rear direction, and if the pop-up camera121 a is drawn out from the second frame 102, it may include arotational camera that enables selfie photographing toward a frontdirection.

As another embodiment, the pop-up camera 121 a may take the front of themobile terminal as the rear camera 121 b located in the rear directionis rotated as much as 180° through hinge movement and changes adirection to the front.

When the pop-up camera 121 a is accommodated in the frame, it may berotated toward the rear and may serve as the rear camera 121 b. Thepop-up camera 121 a and the rear camera 121 b of the mobile terminal maybe implemented as camera modules.

FIGS. 5 and 6 are exploded perspective views of the mobile terminal inaccordance with an embodiment. FIG. 5 is an exploded perspective view ofthe mobile terminal as viewed from the front side, and FIG. 6 is anexploded perspective view of the mobile terminal as viewed from the rearside.

The mobile terminal 100 of the present disclosure includes frames 101and 102 in which components are mounted, and the frames 101 and 102 ofthe present disclosure may vary in size in the first direction as shownin FIG. 2. One or more frames 101 and 102 move relative to each other,and sizes thereof may vary in the first direction. Electronic componentsare mounted in the frames 101 and 102, and the flexible display unit 151is located out of the frames 101 and 102.

Since the mobile terminal 100 of the present disclosure includes theflexible display unit 151, the flexible display unit 151 may be combinedin a form surrounding front faces and rear faces of the frames 101 and102. The frame may include the first frame 101 and the second frame 102moving in the first direction with respect to the first frame 101. Thefirst frame 101 and the second frame 102 include front portions, a rearportions, and side portions, respectively, and are coupled to eachother.

The first frame 101 constitutes the front surface of the mobileterminal, and is coupled to the second frame 102 on the rear surface ofthe first frame 101. The second frame 102 may include a front portion1021, a rear portion 1022, and a main body including a space in whichvarious components are accommodated between side portions forminglateral appearance of the mobile terminal 100. The camera 121, the audiooutput module 152, the input and output terminals, the controller 180and the power supply unit 190 may be accommodated in the space of thesecond frame 101 as the components of the mobile terminal 100. Forexample, the controller 180 may be a processor for controlling theoperation of the mobile terminal 100 and a circuit board 181 includingan electronic circuit, and the power supply unit 190 may be the battery191 and related components. The driving unit 200 for controlling slidemovement of the first frame 101 may be accommodated in the second frame102. An audio hole of an audio output unit 152 a packaged in the secondframe 102 may be formed at the end in the third direction of the secondframe 102, that is, a position which is not overlapped with the firstframe 101, as shown in FIG. 2.

The first frame 101 may slidably be coupled to the front of the secondframe in the second direction, and the first area of the display unit151 is only coupled to the first frame 101 and the other electroniccomponents may all be located in the second frame 102. As describedabove, a front deco 1026 in the third direction and a fourth directionopposite to the third direction may be configured to be coupled to thesecond frame 102 to from the audio hole of the audio output unit 152 ain the second frame 102. An edge deco 1016 serves to fix an end portionof a first area 151 a to the first frame 101. When the mobile terminal100 is extended at the second state, since the end portion in the seconddirection is vulnerable, a metal material may be used to reinforcerigidity.

Also, the front end portion of the flexible display unit 151 may becoupled to the first frame 101 while constituting a curved surface suchthat it may be configured symmetrically with a side portion rolled inthe second direction, and may include a curved surface corresponding tothat of the flexible display unit 151.

As described above, the display unit 151 has the continuous body, andthus, may be disposed on both the front face and the rear face of themobile terminal 100 while being rolled in the mobile terminal 100. Thedisplay unit 151 may include the front face positioned at the front faceof the mobile terminal 100, the rear face positioned at the rear face ofthe mobile terminal 100, and the side face positioned between the frontface and the rear face thereof and surrounding the side face of themobile terminal. The front face and the rear face of the display unit151 are flat, and the side face of the display unit 151 may form acurved face. The flexible display unit 151 may be damaged when beingbent at an angle. Thus, the flexible display unit 151 may be formed tobe bent with a predetermined curvature at the side face.

The display unit 151 may be divided into a fixed portion 151 a and avariable portion 151 b. The fixed portion 151 a means a portion fixed tothe frame. Since the fixed portion is fixed to the frame, it ismaintained at a certain shape without change in its bending level. Onthe other hand, the variable portion 151 b means a portion where anangle of a bent portion is varied or a position of the bent portion isvaried. The variable portion 151 b in which the bent position or angleis varied needs a structure for supporting a rear surface of thevariable portion 151 b to correspond to the above change.

The fixed portion 151 a is coupled to the first frame 101 of the displayunit and always located on the front surface to constitute a portion ofthe front portion. The variable portion 151 b includes a side portionlocated in a side direction of the mobile terminal, and a position ofthe side portion is varied depending on the position of the second frame102. Based on the side portion, an area located on the front surface andan area of the rear surface are varied. That is, the variable portion151 b may partially be the front portion or the rear portion dependingon the first state and the second state. Based on the mobile terminal,the variable portion 151 b is located in the first direction withrespect to the fixed portion 151 a, and an end portion of the variableportion 151 b is bent in a rear direction of the mobile terminal 100 andslidably moves from the rear surface of the second frame 102.

The end portion of the variable portion 151 b of the display unit iscoupled to the slide frame 103 that guides the variable portion 151 b toslidably move on the rear surface of the second frame, and the slideframe 103 moves on the second frame 102 in the first direction when thesecond frame 102 moves in the first direction. As a result, the slideframe 103 moves with respect to the first frame at a distancecorresponding to twice of the second frame 102. In another aspect, aswell shown in FIG. 3, the rear portion 1022 of the mobile terminal 100may include an exposed rear portion 1015 exposed to the outside withoutbeing covered by the display unit 151 even at the first state. Also, thedisplay unit 151 may be rolled in the second frame 102 and bent at 180°to be disposed on both the front surface and the rear surface of themobile terminal 100. For this arrangement of the display unit 151, thesecond frame 102 may include a roller rotatably disposed therein.

However, the display unit 151 should be spread to be flat on the frontsurface and the rear surface of the mobile terminal 100 to provide auser with a screen of good quality. To this end, proper tension shouldbe provided to the display unit 151. To provide proper tension, theroller may be disposed at the end portion in the first direction of thesecond frame 102. The roller may rotatably be coupled to the secondframe 102. A plurality of the rollers 10 may be distributed and disposedin the third direction in consideration of arrangement of componentspackaged in the second frame 102.

The display unit 151 may gently be bent with a predetermined curvatureand rolled in the roller. The flexible display unit 151 may include afirst surface outputting an image, exposed to the outside, and an innersurface headed for the frame at an opposite side of the first surface.The roller may be provided to be freely rotated in the second frame 102while being in contact with the inner surface of the display unit 151.

Also, the roller may be disposed to adjoin the end portion in the firstdirection of the second frame 102, and a side frame 1024 may be disposedat the end portion in the first direction of the second frame 102 toprevent the display unit 151 rolled in the roller, that is, the curvedportion, from being damaged.

The side frame 1024 may longitudinally be extended in a length direction(third direction) of the second frame 102 and may cover the side portionin the first direction, whereby the display unit 151 rolled in the endportion of the first direction of the second frame 102 may be protected.The inner side of the side frame 1024 may include a curved surfacecorresponding to a curvature of the side portion.

The side frame 1024 may substantially form external appearance of themobile terminal 100 together with the side portion 1023 of the firstframe 101. Also, the second frame 102 may be omitted at the side portionin the second direction to minimize interference with the componentswithin the first frame 101 during movement.

Also, the body may extend or downsize the size of the mobile terminal100, particularly the front surface of the mobile terminal 100 byextension and contraction to the first and second directions D1 and D2,and the display unit 151 should move as much as the extended ordownsized front surface to obtain the first and second states which areintended. However, if the display unit 151 is fixed to the second frame102, the display unit 151 cannot actively move to correspond to theextended or downsized front surface of the mobile terminal 100. For thisreason, the display unit 151 may movably be coupled to the second frame102.

In more detail, the display unit 151 may include a first area 151 adisposed on the front surface of the mobile terminal 100 and a secondarea 151 b extended from the first area 151 a in the first direction andbent to surround the second frame 102. The second area 151 b may move tothe front surface or the rear surface in accordance with a state changeof the mobile terminal 100 and switch the front portion to the rearportion or vice versa.

The slide frame 103 may be comprised of a plate shaped memberlongitudinally extended in the length direction (third direction) of themobile terminal 100, and may movably be coupled to the second rearportion 1022 in the first and second directions D1 and D2. The endportion of the second area 151 b may be coupled to the rear surface ofthe slide frame 103, whereby slide movement of the slide frame 103 mayinteract with slide movement of the first frame 101 and the movement ofthe display unit 151.

The respective areas 151 a and 151 b of the display unit 151 may beconnected with each other, and may form a continuous body of the displayunit 151. Also, as described above, for movement of the second area 151b to the front surface or the rear surface of the mobile terminal 100based on the moving direction of the second frame 102, the first area151 is fixed to the front surface of the mobile terminal 100 withoutmovement, and may be movably provided on the rear surface of the mobileterminal 100. This configuration of the display unit 151 will bedescribed in more detail.

The first area 151 a may be disposed on the front surface of the mobileterminal 100, more specifically the front surface of the first frame101. The first area 151 a may be exposed to the front surface of themobile terminal 100.

The second area 151 b is a portion extended to adjoin the first area 151a in the first direction, and surrounds the end portion in the firstdirection of the second frame 102 and is partially disposed on the rearsurface of the mobile terminal 100 to configure the rear portion.

The rear portion of the second area 151 b may be disposed on the rearsurface of the mobile terminal 100, more specifically the rear surfaceof the rear portion 1022 of the second frame 102. The second area 151 bmay be coupled to the slide frame 103 without being directly coupled tothe second frame 102, and may slide on the rear surface of the secondframe 102.

The first area 151 a is disposed on the front surface of the mobileterminal 100 and always exposed to the front surface regardless ofmovement of the second frame 102. The second area 151 b has an area onthe front surface and the rear surface, which is varied depending on themoving directions D1 and D2 of the second frame 102.

A specific location of the foldable mobile terminal in a form of beingspread like a book is easily damaged because only the specific locationis folded repeatedly. On the other hand, a position of the side portionof the flexible display unit 151 may vary based on the first and secondstates of the mobile terminal 100, that is, the movement of the secondframe 102. Accordingly, the mobile terminal 100 of the presentdisclosure may significantly reduce deformation and fatigue repeatedlyapplied to a specific portion of the display unit 151, therebypreventing damage to the display unit 151.

Based on the above-described configuration, overall operations of themobile terminal 100 will be described as follows. As an example, thestate conversion may be performed manually by the user, and an operationof the mobile terminal 100 during such manual state conversion will bedescribed. However, operations of the first to third frames 101 to 103and the display unit 151, which will be described below, may beperformed in the same manner when a power source other than a user'sforce is used, for example, when the driving unit 200 to be describedbelow is applied.

FIG. 7 is a view showing the inside of the mobile terminal 100 accordingto an embodiment, wherein (a) shows a first state and (b) shows a secondstate. The mobile terminal 100 of the present disclosure may be switchedbetween the states in such a manner that a user manually pushes or pullsthe first frame 101 with respect to the second frame 102 in the firstdirection D1 or the second direction D2. However, according to themanual switching, if a force is forcibly applied to a main body of themobile terminal 100, since the mobile terminal 100 may be damaged, themobile terminal 100 may further include a driving unit 200 that uses amotor 201 to stably move the second frame 102 without distortion.

A motor for providing a rotational force as shown in FIG. 7 may be usedas the motor 201, or a linear motor 201 configured to make linear motionmay be used. The motor 201 for providing the rotational force shouldhave a large diameter to provide large force. Two motors 201 may be usedas shown in FIG. 7 to provide a driving force of a predetermined size ormore in the limited space of the mobile terminal 100 without increasingthe thickness.

Since the second frame 102 linearly moves with respect to the firstframe 101 in the first direction or the second direction, a rack piniongear 202 configured to convert the rotational force of the motor 201into linear motion may be used. The pinion gear 202 configured toreceive the rotational force of the motor 201 may be arranged to beengaged with a rack gear 205 composed of teeth continuously arranged inthe first direction. The pinion gear 202 may be fixed to the first frame101 together with the motor 201 and the rack gear 205 may be positionedon the second frame 102. On the contrary, the rack gear 205 may bepositioned on the first frame 101, and the motor 201 and the pinion gear202 may be arranged on the second frame 102. Since the motor 201 holdsthe pinion gear 202 such that the pinion gear 202 does not rotate, thesecond frame 102 may maintain the first state and the second state.However, when a large external force is applied, the second frame 102may be dislocated as the pinion gear 202 rotates.

A stopper (not shown) configured to fix the positions of the secondframe 102 or between the rack gear 205 and the first frame 101 may befurther provided to fix the mobile terminal 100 at the first state orthe second state. When electric current flows through the motor 201 todrive the motor 201, the stopper may be released to allow the movementof the second frame 102. When a power source is not applied to the motor201 and thus the motor 201 does not rotate, the stopper may be fastenedto fix the positions of the first frame 101 and the second frame 102.

In order to arrange a battery or the like in consideration of thelimited packaging space of the mobile terminal 100, the driving unit 200may be disposed to be biased to one side as shown in FIG. 7(a).

According to such asymmetric arrangement of the driving unit 200, thesecond frame 102 may be distorted during movement due to a difference inmoving speed between an upper end portion and a lower end portion. Toaddress this issue, a linear guide 230 may be further provided. Thelinear guide 230 may be disposed to be spaced in the third direction ofthe mobile terminal 100 to supplement the function of one driving unit200 biased to one side in the third direction. The linear guide 230 mayinclude a guide rail 231 extended in the first direction and a guideblock 232 configured to move along the guide rail 231. The guide rail231 may be disposed on the first frame 101 and the guide block 232 maybe disposed on the second frame 102, or vice versa as shown in FIG. 7.

After the guide block 232 is coupled to the first frame 101 and theguide rail 231 is coupled to the second frame 102, the guide block 232and the guide rail 231 may be slidably fastened to each other. However,for convenience of the fastening, the guide block 232 and the guide rail231 fastened to each other. Then, the guide block 232 may be first fixedto the first frame 101, and then the second frame 102 may be coupled tothe guide rail 231.

The guide block 232 may be provided with a guide groove into which theguide rail 231 is inserted. Alternatively, the guide rail 231 may beprovided with a rail groove into which a portion of the guide block 232is inserted. The fastening portions of the guide rail 231 and the guideblock 232 may be formed to be bumpy. Accordingly, movement in the firstdirection or the second direction may be made without displacement inthe thickness direction of the mobile terminal 100. In order to reducefriction between the guide block 232 and the guide rail 231, aself-lubricating member having high wear resistance and low frictionresistance, such as a bearing or polyoxymethylene (POM), may be added tothe inside of the guide groove.

FIG. 8 is a view showing the inside of the mobile terminal 100 accordingto another embodiment. Unlike the aforementioned embodiment, a pair ofmotors 201 are disposed to be spaced apart from each other in an up anddown direction.

As described above, the biased arrangement of the motor 201 has aproblem that the first frame 101 is biased to one side during movement.If upper and lower sides of the mobile terminal 100 do not move at thesame speed, an error operation of the motor 201 may occur, and a tensileforce occurs in one side of the flexible display unit 151 andcontraction occurs in the other side of the flexible display unit,whereby the flexible display unit 151 may be damaged.

If the pair of motors 201 are disposed to be spaced apart from eachother in an up and down direction, a sufficient driving force may beprovided thereto and distortion in the up and down direction may beavoided. Also, since the driving units 200 disposed in the up and downdirection keep balance in the up and down direction, a separate linearguide 230 may be omitted.

FIG. 9 is a view showing the driving unit 200 of the mobile terminal inaccordance with an embodiment. The driving unit 200 includes a motor201, a planet gear and a pinion gear 202 for adjusting RPM of the motor201, a rack gear 205 engaged with the pinion gear 202, making linearmovement by a rotational force of the pinion gear 202, and a motorhousing 204 in which the motor 201, the planet gear and the pinion gear202 are accommodated. FIG. 9(a) is a plane view of the driving unit,FIG. 9(b) is a cross-sectional view taken along line C-C of FIG. 9(a),and FIG. 9(c) is a perspective view showing a portion corresponding tothe motor housing 204 and the pinion gear 202 in a state that the rackgear 205 is removed.

The rack gear 205 has teeth formed on a surface headed for the piniongear 202 and thus engaged with the pinion gear 202, wherein the teethmay be continuously formed in the first direction. An edge portion 2052which is not provided with teeth may be further provided at bothportions of the portion where the teeth are formed.

The motor housing 204 may expose the pinion gear 202 to allow the rackgear 205 and the pinion gear 202 may move while adjoining each other,and may further include a rack gear guide located in the third directionof the rack gear 205 such that the rack gear 205 is not vibrated in thethird direction. The rack gear guide guides a slide moving direction ofthe rack gear 205 in contact with the edge portion 2052 of the rack gear205. However, if the rack gear guide is in contact with the rack gear205, problems occur in that friction occurs during slide movement andthe driving force of the driving unit 200 is deteriorated.

Rail bearings 204 a and 2054 may be provided as shown in FIGS. 9(b) and((c) to reduce friction between the rack gear guide and the rack gear205. The rail bearings 204 a and 2054 include a plurality of bearingballs 204 a that reduce friction while rotating when the rack gear 205slidably moves between the rack gear guide and the edge portion 2052 ofthe rack gear 205. The ball rail 2054 including a curved surfacecorresponding to that of the bearing ball 204 a may be formed at theside of the rack gear 205 and the gear guide to allow the bearing ball204 a not to be detached therefrom.

Although the driving unit 200 having one motor 201 is shown, two motors201 may be provided as shown in FIG. 7, and if the rail bearings 204 aand 2054 are applied to the gear guide, the linear guide 230 may bereplaced with the gear guide.

FIG. 10 is a cross-sectional view taken along lines A-A and B-B in FIG.2. As shown in FIG. 2, if the second frame 102 moves in the firstdirection and then is switched to the second state, a structure formoving the second area 151 b, which is located in the rear direction, ina front direction and supporting the rear surface of the moved secondarea 151 b is required. Although the front portion 1021 located on thefront surface of the second frame 102 may be located on the rear surfaceof the second area 151 b at the second state, since the front portion1021 is disposed on the rear surface of the first frame 101 at the firststate, a step difference occurs between the front surface of the firstframe 101 and the front surface of the second frame 102 at the secondstate.

A boundary may occur in the first area 151 a and the second area 151 bof the flexible display unit 151 by the step difference between thefront surface of the first frame 101 and the front surface of the secondframe 102. A rolling hinge 104 located on the rear surface of the secondarea 151 b may be provided to fill a gap space between the front portion1021 of the second frame and the second area 151 b of the flexibledisplay unit 151 and maintain a flat surface of the second area 151 bwithout sagging down.

The rolling hinge 104 may be located on the rear surface of the secondarea 151 b, and may have a thickness corresponding to the gap spacebetween the front portion 1021 of the second frame 102 and the secondarea 151 b of the flexible display unit 151, at the second state. Asshown in FIG. 10(a), the rolling hinge 104 may be rolled in the roller210 at the first state and located on the front surface, the side andthe rear surface of the mobile terminal 100.

As shown in FIG. 10(a), at the first state, the slide frame 103, theflexible display unit 151 and the rolling hinge 104 may be locatedbetween the rear portion 1022 of the second frame 102 and the rear cover1025 covering the rear portion of the display unit 151.

As shown in FIG. 10(b), the rolling hinge 104 moves to the front surfacetogether with the second area 151 b during switching to the secondstate, and may be located at the front of the second frame 102. Theslide frame 103 may move between the rear portion 1022 of the secondframe and the rear cover 1025.

Since the second area 151 b of the display unit 151, in which therolling hinge 104 is located, is the portion where bending deformationoccurs during switching from the first state to the second state, therolling hinge 104 may be deformed to correspond to deformation of thesecond area 151 b. At the same time, the rolling hinge 104 should havepredetermined rigidity to maintain a flat state if the flexible displayunit 151 is located on the front surface or the rear surface. That is,the rolling hinge 104 needs a structure for maintaining the flat statein the third direction and enabling bending deformation in the firstdirection.

FIG. 11 is a view showing a display unit 151 and a rolling hinge 104 ofthe mobile terminal 100 in accordance with an embodiment. The rollinghinge 104 may include multiple support bars 1041 extending in the thirddirection. The multiple support bars 1041 may be arranged side by sidein the first direction and spaced apart from each other by apredetermined distance. Accordingly, even when the flexible display unit151 is rolled around the roller 210 and is thus bent, interferencebetween the support bars 1041 may be avoided. The support bars 1041 maybe implemented with an injection molding material having a predeterminedthickness for stiffness, and may include materials such as SUS orferrosilicon (FeSi).

The multiple support bars 1041 may be directly attached to the rearsurface of the display unit 151. However, this operation may take a longtime and produce a lot of defects, resulting in poor productivity. Inaddition, directly processing the display unit 151 is highly likely todamage the display unit 151. Therefore, a rolling sheet 1045 to fix themultiple support bars 1041 may be further provided. The rolling sheet1045 may include a metal material, and may employ a superelasticmaterial that is bending-deformable and capable of recovering the flatstate after the bending deformation. For example, a superelastic metalsheet such as a thin STS sheet of 0.05 mm or less may be used. Anadhesive tape may be attached to both surfaces of the rolling sheet 1045to bond the rolling sheet 1045 to the support bars 1041 and bond therear surface of the display unit 151 to the rolling sheet 1045.

The rolling sheet 1045 may be provided with a kerf pattern in whichmultiple grooves extending in the third direction are formed in thefirst direction. The grooves in the kerf pattern may be formed betweenthe multiple support bars 1041. The grooves may be formed on a surfaceof the rolling sheet 1045 to which the support bars 1041 are bonded. Thekerf pattern may be formed in a wedge shape that is formed by beinggradually narrowed from the surface portion of the rolling sheet 1045.

Instead of the rolling sheet 1045, an elastic material such as siliconemay be disposed between the support bars 1041 to join neighboringsupport bars 1041. In this case, the angle between the support bars 1041may be varied. The elastic connector may be bent at a positioncorresponding to the roller 210. When positioned on the front or rear ofthe mobile terminal, the elastic connector may be unfolded such that thesupport bars 1041 are disposed forming a flat surface.

The support bars 1041 may form a flat surface corresponding to the rearsurface of the display unit 151. Alternatively, as shown in FIG. 8(b),the support bars 1041 may be formed in a shape having a predeterminedcurvature. The curved support bars 1041 may closely contact the curvedsurface of the roller 210 when the rolling hinge 104 is rolled aroundthe roller 210. Alternatively, one surface of the support bars 1041 incontact with the display unit 151 maintains a flat state, and the othersurface thereof on the opposite side may include a curved surfacecorresponding to the curvature of the roller 210. In this case, thesupport bars 1041 may be thick at the ends thereof facing in the firstand second directions and have the thinnest portion in the middlethereof.

The rolling hinge 104 is disposed at the position corresponding to thesecond area 151 b, bent by being rolled in the roller 210 and extendsthe front surface and the rear surface. The rolling hinge 104 isconnected with the first frame 101 in a front direction and connectedwith the slide frame 103 in the rear direction. In order that theflexible display unit 151 forms a continuous surface without stepdifference, the first frame 101 located on the rear surface of the firstarea 151 a and a surface adjoining the display unit 151 of the rollinghinge 104 located on the rear surface of the second area 151 b may havethe same height. Particularly, since the slide frame 103 moves on therear surface of the mobile terminal 100 and moves in the same space asthe rolling hinge 104, the rolling hinge 104 may have a thicknesscorresponding to that of the slide frame 103.

FIGS. 12 and 13 are views showing the first frame 101 and the secondframe 102 at the second state of the mobile terminal 100. FIG. 12(a) andFIG. 13(a) are views showing that the display unit 151 is omitted. FIG.12(b) and FIG. 13(b) are sections of D-D in FIG. 12(a) and E-E in FIG.13(a). FIG. 13(c) is a section of F-F in FIG. 13(a).

Referring to FIG. 10, the first frame 101 has a plate shape without aninner space, and the first frame 101 should support the first area atthe second state. If the thickness of the first frame 101 is too thin,since the first frame 101 is vulnerable to rigidity at the second state,the first frame 101 needs to have rigidity of a certain size or more.

If the thickness of the first frame 101 is thick, as shown in FIG.12(b), a thickness gap occurs between the rolling hinge 104 and thefirst frame 101. Sagging occurs in the second area 151 b due to thethickness gap, whereby the boundary between the first area 151 a and thesecond area 151 b of the display unit 151 may be remarkable.

If the rolling hinge 104 is formed thickly to correspond to thethickness of the first frame 101, a curvature radius should be increasedat the portion where the rolling hinge is bent to surround the secondframe 102. If the curvature radius of the rolling hinge 104 isincreased, a problem occurs in that the thickness of the mobile terminal100 becomes thick.

Therefore, the rolling hinge 104 needs to be configured so as not togenerate a gap between the front portion of the second frame 102 and therolling hinge 104 while making sure of rigidity of the first frame 101.A reinforcing rib 1018 protruded from the rear surface of the firstframe 101 and supports 1028 protruded from the front surface of thesecond frame 102 are shown. The reinforcing rib 1018 is disposed on therear surface of the first frame 101 such that a plurality of reinforcingribs are spaced apart from one another in the third direction, whereineach reinforcing rib 1018 is longitudinally extended in the firstdirection. The reinforcing rib 1018 may make sure of rigidity of apredetermined size or more even though the whole thickness of the firstframe 101 is not thick.

The supports 1028 are located among the plurality of reinforcing ribs1018, and are disposed so as not to overlap the reinforcing ribs 1018 inthe first direction. As shown in FIG. 13(c), the supports 1028 may beformed to fully fill the spaces among the reinforcing ribs 1018, and agap space may be provided between the reinforcing rib 1018 and thesupport 1028 in the third direction. Since the reinforcing ribs 1018 arenot overlapped with the supports 1028 in the first direction, thereinforcing ribs 1018 and the supports 1028 do not disturb movement ofthe first frame 101.

A thickness direction height in the thickness direction of the supports1028 may be formed to correspond to that of the reinforcing rib 1028.The supports 1028 may support the rear surface of the rolling hinge 104to remove a gap between the rolling hinge 104 and the front portion ofthe second frame 102, whereby the second area may stably be supportedeven at the second state without sagging in the rear direction.

FIG. 14 is an enlarged view of a portion G of FIG. 13(c), and relates toan embodiment of a third direction section of the reinforcing rib 1018and the support 1028 in FIG. 13. When first frame 101 slidably moves byusing the reinforcing rib 1018 and the support 1028, distortion may beavoided and the linear guide 230 may be implemented. In order to performthe function of the linear guide 230 by using the reinforcing rib 1018and the support 1028, as shown in FIG. 14, the shape of the support 1028may be configured to surround the reinforcing rib 1018 at both sides inthe third direction.

The reinforcing rib 1018 may further include rib protrusion 1018 aprotruded in the third direction, and the support 1028 may include a ribgroove 1028 a corresponding to the rib protrusion of the reinforcing rib1018. The rib protrusion 1018 a and the rib groove 1028 a may havesections of uneven shapes engaged with each other, and may be extendedin the first direction to guide movement of the first frame 101 in thefirst and second directions and limit movement of the first frame 101 inthe third direction, whereby distortion may be prevented from occurring.The section in the third direction of the reinforcing rib 1018 may be arectangular shaped section as shown in FIG. 13(c) but may be a circularshaped section or trapezoidal section in which the rib protrusion 1018 ais formed as shown in FIG. 14(a). The rib groove 1028 a may have aconcave shape corresponding to the rib protrusion 1018 a.

As shown in FIG. 14(c), the rib protrusion 1018 a may have an unevenshape protruded from the end in the thickness direction of thereinforcing rib 1018 in the third direction. As shown in FIG. 14(d), aplurality of reinforcing ribs 1018 and a plurality of supports 1028include a plurality of uneven patterns protruded or inserted in thethird direction to prevent the first frame from moving in the thirddirection or prevent a gap of the first frame from occurring in thethickness direction.

If a width of the section of the rib protrusion 1018 a is increased orbent as the rib protrusion 1018 a is spaced apart from the rear surfaceof the first frame 101, the first frame 101 and the second frame 102 maybe prevented from being detached from each other in the thicknessdirection of the mobile terminal, whereby distortion in the thirddirection may be prevented from occurring and fastening between thefirst frame 101 and the second frame 102 may be enhanced.

As described above, the mobile terminal of the present disclosure mayenhance usability and portability by varying its size.

Also, since the curved portion of the flexible display unit 151 is notlimited to a specific portion, stress only applied to the specificportion may be distributed when a size of the mobile terminal ischanged.

Also, since the display unit 151 may stably be maintained at a flatstate even in the case that mobile terminal 100 is extended, acontinuous large screen may be implemented in an extended state.

Also, since the mobile terminal may naturally be slid withoutdistortion, the mobile terminal may be prevented from being damaged ordisordered in the middle of being used.

Also, the rack gear 205 may be prevented from being exposed to theoutside in a state that the rack gear 205 is extended, whereby acontaminant may be prevented from entering the mobile terminal anddurability may be improved.

As the present features may be embodied in several forms withoutdeparting from the characteristics thereof, it should also be understoodthat the above-described embodiments are not limited by any of thedetails of the foregoing description, unless otherwise specified, butrather should be considered broadly within its scope as defined in theappended claims, and therefore all changes and modifications that fallwithin the metes and bounds of the claims, or equivalents of such metesand bounds, are therefore intended to be embraced by the appendedclaims.

1. A mobile terminal comprising: a body including a first frame and asecond frame slidably coupled to a rear surface of the first frame withrespect to a first direction or a second direction; a flexible displayincluding a first area coupled to a front surface of the first frame,and a second area having a position that varies with respect to a frontsurface or a rear surface of the body when a size of the body ischanged, wherein a rolling hinge is located at a rear surface of thesecond area and configured to enable a bending deformation correspondingto a shape of the second area; a plurality of reinforcing ribsprotruding from the rear surface of the first frame and extending alongthe first direction; and a plurality of supports protruding from a frontsurface of the second frame and located between respective reinforcingribs of the plurality of reinforcing ribs, wherein a thickness of therolling hinge and a thickness of the plurality of supports correspond,respectively, to a thickness of the first frame and a thickness of theplurality of reinforcing ribs.
 2. The mobile terminal of claim 1,wherein each of the plurality of supports has a protruding heightcorresponding to a protruding height of a corresponding reinforcing ribof the plurality of reinforcing ribs.
 3. The mobile terminal of claim 1,wherein: each of the plurality of reinforcing ribs includes a ribprotrusion protruding along a third direction perpendicular to the firstdirection; each of the plurality of supports has a rib groovecorresponding to a shape of the rib protrusion of a correspondingreinforcing rib of the plurality of reinforcing ribs; and the ribprotrusion of each of the plurality of reinforcing ribs and the ribgroove of each of the plurality of supports are configured to guidemovement of the first frame along the first direction and the seconddirection with respect to the second frame and limit movement of thefirst frame along the third direction.
 4. The mobile terminal of claim3, wherein: the rib protrusion of each of the plurality of reinforcingribs includes a low friction layer on a surface thereof; and the ribgroove of each of the plurality of supports includes a low frictionlayer on a surface thereof.
 5. (canceled)
 6. The mobile terminal ofclaim 1, wherein the rolling hinge includes a plurality of support barsextending along a third direction perpendicular to the first directionand disposed in parallel with one another along the first direction, andwherein an interval between support bars of the plurality of supportbars is widened as the support bars are moved further away from a rearof the flexible display.
 7. The mobile terminal of claim 1, furthercomprising a driver configured to move the first frame along the firstdirection or the second direction with respect to the second frame toadjust a size of the body, wherein the driver includes: a motor packagedin the second frame; a pinion gear rotatable by a driving force of themotor; and a rack gear located at the rear surface of the first frameand extending along the first direction, the rack gear configured tomove linearly by the driving force of the motor, which is deliveredthrough the pinion gear.
 8. The mobile terminal of claim 7, furthercomprising: a motor housing fastened to the second frame and configuredto seat the motor and the pinion gear thereon; and a guide rail fastenedto the rack gear and configured to guide the linear movement of the rackgear.
 9. The mobile terminal of claim 8, further comprising a railbearing located between the guide rail and the rack gear.
 10. The mobileterminal of claim 7, wherein the driver further includes: a plurality ofmotors disposed in parallel with one another along the first direction;and a plurality of pinion gears fastened to the plurality of motors, andconfigured to deliver the driving force to the rack gear.
 11. The mobileterminal of claim 7, wherein the driver further includes a plurality ofdrivers disposed to be spaced apart from one another with respect to athird direction perpendicular to the first direction.
 12. The mobileterminal of claim 1, further comprising a slide frame slidably coupledto a rear surface of the second frame with respect to the firstdirection or the second direction, wherein an end portion of theflexible display is fixed to a rear surface of the slide frame.
 13. Themobile terminal of claim 12, further comprising a first edge deco fixingthe end portion of the flexible display to the first frame.
 14. Themobile terminal of claim 1, wherein the second area includes a sideportion surrounding a side of the body, and wherein the mobile terminalfurther comprises a side frame configured to protect the side portion ofthe flexible display.
 15. The mobile terminal of claim 1, furthercomprising a rear cover covering a rear surface of the second frame, therear cover including a light-transmissive material.
 16. A mobileterminal comprising: a body including a first frame and a second frameslidably coupled to a rear surface of the first frame with respect to afirst direction or a second direction; a flexible display including afirst area coupled to a front surface of the first frame, and a secondarea having a position that varies with respect to a front surface or arear surface of the body when a size of the body is changed; and adriver configured to move the first frame along the first direction orthe second direction with respect to the second frame to adjust the sizeof the body, wherein the driver includes: a motor housing fastened tothe second frame; a motor packaged in the motor housing; a pinion gearpackaged in the motor housing and rotatable by a driving force of themotor; a rack gear located at the first frame and extending along thefirst direction, the rack gear configured to move linearly by thedriving force of the motor, which is delivered through the pinion gear;and a rack gear guide formed at the motor housing and configured toguide the linear movement of the rack gear.
 17. The mobile terminal ofclaim 16, further comprising a rail bearing located between the rackgear guide and the rack gear.
 18. The mobile terminal of claim 16,wherein the driver further includes a plurality of drivers disposed tobe spaced apart from one another with respect to a third directionperpendicular to the first direction.
 19. A mobile terminal comprising:a body including a first frame and a second frame slidably coupled to arear surface of the first frame with respect to a first direction or asecond direction; a flexible display including a first area coupled to afront surface of the first frame, and a second area having a positionthat varies with respect to a front surface or a rear surface of thebody when a size of the body is changed; and a driver configured to movethe first frame along the first direction or the second direction withrespect to the second frame to adjust the size of the body, wherein thedriver includes: a plurality of motors packaged in the second frame anddisposed in parallel with one another along the first direction; a rackgear located at the first frame and extending along the first direction;and a plurality of pinion gears fastened to the plurality of motors, andconfigured to deliver a driving force to the rack gear.
 20. The mobileterminal of claim 19, further comprising: a motor housing fastened tothe second frame and configured to seat the plurality of motors and theplurality of pinion gears thereon; and a guide rail fastened to the rackgear and configured to guide a linear movement of the rack gear.